Fuel pump relay circuit problems disturb the power supply to the fuel pump for the required amount of delivery towards the engine. The failure of the relay itself is a common failure on the circuit, in which a complete closure of the electrical circuit may not occur for the operation of the pump. Most of the relays run on a 12-volt system, and any kind of voltage drop-like that caused by a weak battery-will not allow the proper functioning of the relay. Automotive experts explain that even a slight voltage drop down to approximately 10 volts will reduce the efficiency of the fuel pump up to 15% and result in fuel starvation when demand goes high.
Another common problem is corrosion in the relay circuit due to prevailing in high humidity or salt-rich atmospheres. Corrosion on the terminals or connectors raises the electrical resistance, thereby reducing the current supplied to the fuel pump. A corroded relay circuit can decrease pump performance by 10% to 20%, making an engine more difficult to start, and it may cause rough idling. The regular inspection of the relay and connectors will prevent these problems. This is most important in older vehicles where corrosion is commonplace.
Wiring problems in the relay circuit, such as frayed or loose wires, also cause intermittent power losses to the fuel pump. Therefore, as this wiring wears out, sometimes it can have power that is inconsistent, which will make the pump work sporadically. This may eventually lead to misfires, stalling, and poor timely delivery of fuel. Repair of faulty wiring: Costs anywhere from about $50 to $100, which is close to nothing compared with bigger failures in the fuel system.
Overheating of a relay also occurs in terms of circuit performance. An overheated relay, either from an extended use or due to electrical resistance, may not be capable of supplying the constant power called for by the fuel pump. It may not be able to sustain the required pressure, usually within the bracket of 40 to 60 PSI, thus creating a problem in the delivery of fuel and causing hesitation of the engine. Relays generally cost very cheap, such as 20 to 50 dollars, but regular maintenance by replacing them avoids a big deal.
Sometimes, the ECU or Engine Control Unit has glitches that could potentially be the cause of relay circuit failures. Usually, an ECU governs the timing and turning on of the relays. In cases where the ECU develops some sort of malfunction, it might not allow proper engagement of the relay. ECU-related problems in relays may require professional diagnosis and repairs ranging from about $200 to $500, depending on the level of the issue at hand.
These are the issues that can affect the life span and reliability of the Fuel Pump itself, since the pump is strained and has to work under inconsistent conditions. Early remedies of relay circuit issues ensure efficient fuel delivery and protect the health of the engine and overall vehicle performance.